My mother was always there. She was there as soon as I was aware of anything. And she was there until she was 96. She was a hell of a presence. I owe her a greater debt than most children could possibly owe a parent.

I was born outside of marriage – the child of a one-parent family. My mother, a Roman Catholic, refused my father's instruction to abort me and educated me as best she could. She gave me an education of extraordinary depth. I'd ask about a star and we'd lie on our backs on Whitstable beach and she'd tell me what all the stars were. Then we'd launch into Greek mythology. I was reading the Argonauts in no time at all. When I eventually went to school at the age of 11, my education was already very well formed in totally unsuitable ways. It's all very well knowing about Greek myths, but what about algebra? Well, bugger algebra. And I never did catch up. I wish I'd spent more time on Greek myths.

My mother may have been something of a prostitute, though perhaps that is too strong a word. When we lived in Whitstable, she would give me a slug of cherry brandy and go out, late at night, leaving me with our dog. Well, where do you go in Whitstable, and why do you go? There were also evenings in London when she would go out in her evening dress and not return until the next morning. What was it?

As a child, I did not miss my father and was not curious until, when I was 10, my mother married my stepfather and they attempted to convince me he was my true father. Decades later, I discovered my real father was Philip Heseltine, better known as Peter Warlock, a minor composer. My mother had been one of his several mistresses. They had a blazing row over the abortion issue and the next thing she knew he had put his head in the gas oven. I think she bore the guilt for the rest of her life.

My father was sexually voracious, happiest with three in his bed – men or women. His tastes ran to sadism and were said to include flagellation. But the thing that appals me is that his remedy for pregnancy was abortion – without hesitation. He just waved a £5 note at my mother and told her to get on with it. The only thing I like about my father is that he took pains to put his young cat out before he turned the gas on. I will forgive him everything for that.

My mother carried an air of tragedy because, like me, she had great promise and it was unfulfilled. She was a very good painter and a brilliant cellist, but was never able to make anything of either. She would have had me a violinist above all, but I was never going to be anything better than the back of the second fiddle in a provincial orchestra. That's one reason why I'm grateful for national service because it was an enforced break.

My mother came to live with me in later life. The first 13 years were fine; the second 13 were after her stroke, when she sank into physical and mental decline. The really awful thing was the change in our relationship because she had been more like a sister, and the sister bit disappeared. She became suspicious and vituperative. She was angry with the world and constantly angry with me. It was almost as if she hated me.

When you reach your 20s, people start asking questions. When is the girl coming? My crisis point was a fellow student at the Courtauld Institute. It would have been so much easier to have said to her: "Why don't we get married instead of you marrying your fiance?" It was a temptation. But it was a temptation that so many homosexuals of my generation fell for and it would have been disastrous. It would have been another lie. Better to be alone than the husband of some termagant, being dragged around the supermarket.